Throughout the industrial arts, there is an ever-increasing provision and use of pneumatically powered hand tools. Such pneumatic tools include manually engageable rotary drive tools for fastener driving sockets; grinding and/or sanding wheels and the like; manually engageable axially driven impact tools for chisels, riveting tools and the like; and reciprocating drive tools for operating various work performing devices such as staplers, nailing machines and wire bending devices.
In addition to the above noted general types and classes of hand tools, there is an increasing number of specialized pneumatic hand tools. Included among these specialized tools are pneumatically powered, hand-actuated agricultural shears for trimming grape vines, fruit trees and the like. One such pneumatically powered, hand operated shears is the "Super Star" Model SF, manufactured by Campagnola in Bologna, Italy.
For the purpose of describing my invention, I will show and describe my back pack pneumatic power supply unit related to and supplying motive air to a manually operated pneumatically powered shears. It is to be understood that in practice, the power supply unit that I provide can be advantageously used to supply motive air to a multiplicity of other and different tools and devices without departing from the broader aspects and spirit of my invention.
In the prior art, where pneumatically powered hand tools are used, the use of such tools has been limited and/or restricted to relatively small and/or restricted areas within close proximity to and about common or conventional stationary high pressure air supplies consisting of large and heavy motor driven compressors and large, heavy air supply tanks. The range of use of such tools has, as a general rule, been limited to that length of flexible air supply hose that can be effectively, conveniently and safely used to connect the hand tools with their related stationary air supplies.
While the prior art provides air supply units which are sufficiently small and light so that they can be supported by means of wheels and manually moved about from one site to another, they are not "portable" in the sense that they can be physically carried about by the users thereof, when in operation and as the users thereof are carrying out the work that is to be performed.
As a result of the foregoing, we have recognized the great need for a small, compact, lightweight pneumatic power supply unit for pneumatically powered hand tools which can be advantageously supported on the backs of and carried by the users of pneumatically powered hand tools whereby the range of use of such tools is not limited by the length of air supply hoses that can be used and is not dependent upon continuously or intermittently transporting and moving a separate air supply means from one work site to another during normal and intended ongoing or continuous use of the hand tools.